High-frequency power supply to multiple loads



NOV. 30, 1948. J 5, N L 1 2,454,784

HIGH-FREQUENCY POWER SUPPLY TO MULTIPLE LOADS Filed March 29, 1944 e 1' 4 AMPLIFIER HIGH r FREQUENCYI SOURCE INVENTOR TAMES 5. ENGEL.

BY ATTOR EY Patented Nov. 30, i948 HIGH-FREQUENCY POWER SUPPLY TO 1 MULTIPLE LOADS James S. Engel, New

York, N Y., a. corporat Application March 29, 1

Rochelle, N. Y., assignor. to Federal Telephone an d Radio Corporation, New

ionof Delaware 944, Serial No. 528,552

3 Claims; (Cl. 178-44) This invention relates to high frequency apparatus and has for its principal object to provide circuits ior supplying multiple high frequency power loads from a singlesource of poweri Another object of the invention is to provide circuits for feeding a plurality of loads from a balanced high frequency circuit without disturbing the balance of the circuit.

Still another object of the invention is to provide a circuit for feeding load circuits from a balanced high frequency supply circuit in which the amount of power absorbed by the various load circuits may be adjusted without disturbing the balance of the balanced supply circuit.

Still another object of the invention is to provide a circuit for removing power from a link,

used to couple a balanced power supply circuit to a load circuit, without unbalancing said supply circuit.

Other objects of the invention will be apparent as the description proceeds.

One embodiment of the invention has been illustrated in the accompanying drawing in which the single figure shows the circuit for delivering power to two additional load circuits besides the main load circuit of the system.

In the embodiment used to illustrate the invention a high frequency supply circuit l which is of the push-pull type is shown with an output circuit 2 comprising a conducting loop which is con-- nected to the plates of two output tubes, as represented at 3 and 4. A conducting link 5 is shown inductively coupled to the loop 2 and is in turn inductively coupled to a loop 6 which is the input circuit of an output amplifier 1', the loop being attached to the grids of the input tubes which are indicated at 8 and 9. The amplifier 1 may have its output connected to an antenna or other load circuit.

It is difficult to remove additional power from the push-pull balanced type of circuit, described above, without upsetting the balance of the highfrequency supply circuit I. By means of this invention, however, it is possible to remove power and feed it to two different load circuits without upsetting the balance. To this end a conductive link It! is inductively coupled to the link 5 and also to an inductance a dual-section condenser l2, thus forming a high impedance tuned circuit. The condenser l2 has two sets of stator plates, one being connected to one end of the inductance I l and the other being connected to the other end of the inductance, and a plurality of rotor plates which cooperate capacil I across which is connected tivelywith the stator plates. The rotor plates are connected to ground so that the tuned circuit ll'-l2 is balanced with respect to ground. This type of dual-section condenser is well known in the art.

A low impedance circuit comprising an inductance l3 and variable condenser M in series with the inductance is connected between ground and one side of the high impedance circuit ll--l2, the connection being made to the junction between one end of the inductance H and one set of stator plates inthe condenser 12. Another low impedance circuit comprising an inductance l5 and a variablecondenser l6 connected in series with the inductance is connected between ground and the other side of the high impedance circuit l |-l 2, the connection being made to the junction between the, other end of the inductance H and the other set of stator plates of the condenser 12.

An inductance I! may be coupled to the inductance l3 and is connected between ground and the central conductor of a coaxial transmission line I8, the outside conductor of which is connected to ground. Likewise, an inductance I9 is coupled to the inductance l5 and is connected between ground and the central conductorof a coaxial line 20, the outer conductor of which is connected to ground. The circuits including the inductan-ces l1 and I9 are untuned and the transmission lines 18 and 20 lead to any desirable lo-ad circuits.

In operating the circuit of the invention the high impedance circuit H--l2 is tuned to the frequency of the power being transmitted between the power source I and the amplifier 1. Power will then be supplied to the high impedance circuit H-l2 through the coupling link In. Because of the balanced condition of the high impedance circuit H--l2 the balance of the power source i will not be disturbed, and because of the difference in impedance between the circuit ll-l2 and the low impedance circuits l3--l4 and 15-46, power can be supplied to these latter circuits without unbalancing the high impedance circuit ll-l2. The low impedance circuits |3-l4 and i5-.-l6 will then deliver power to the inductances l1 and I9, respectively, and thus to the transmission lines l8 and 20, respectively.

The amount of power received by each transmission line will depend on the setting of the condensers l4 and I6. These may be adjusted so that equal amounts of power may be removed by the two transmission lines, or it is possible to adjust these condensers so that very little or sub-.

stantially no power is delivered to one, so that power is fed only to the other.

The circuit of the invention forms a convenient method of delivering power from a single balanced source to two or three separate load circuits. The diagram shows three separate load circuits, but it will be-ev'ident that the amplifier- 1 and input loop 6 might be eliminated, in which case the power would be delivered through the transmission lines l8 and 20 in any desired pro-- portions depending on densers l4 and I6.

What is claimed is: 1. A high frequency circuit comprising'a source of high frequency power having abalanced out?- the adjustmentof the con-- put circuit, a high impedance circuit tuned to the frequency of said source, means coupling: said high impedance circuit to said balanced. output circuit in such manner as to maintain the latter in balance, means to balance said high, impedance circuit with respect to ground, a pair of low impedance circuits, one connected between one side of said high impedance circuit and ground and the other'connected between the other side and ground, and a pair of output circuits, one coupled to each of said low impedance circuits.

JAMES S. ENGEL.

REFERENCES CITED The following references are of record in the .file. or". this patent:

UNITED STATES PATENTS Number Name Date 2,272,452 Whittle Feb. 10, 1942 2,359,618 Byrne Oct; 3, 1944 2,370,724 Ferrill, Jr. Mar; 6, 1945- 

